[PATCH] spi: spi-omap2-mcspi.c: Add dts for slave device configuration.

[Matthias Brugger]

Hello,

2013/3/26 Matthias Brugger <matthias.bgg at gmail.com>

> TI omap2 mcspi allows the slave devices to configure the behavior of
> the SPI master. This patch adds device tree support to the existing
> options.
>
> Signed-off-by: Matthias Brugger <matthias.bgg at gmail.com>
> ---
>

Any comments on this patch?


>  Documentation/devicetree/bindings/spi/omap-spi.txt | 23 ++++++++++++
>  drivers/spi/spi-omap2-mcspi.c                      | 41
> ++++++++++++++++++++++
>  2 files changed, 64 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/spi/omap-spi.txt
> b/Documentation/devicetree/bindings/spi/omap-spi.txt
> index 938809c..fef16bf 100644
> --- a/Documentation/devicetree/bindings/spi/omap-spi.txt
> +++ b/Documentation/devicetree/bindings/spi/omap-spi.txt
> @@ -10,8 +10,20 @@ Required properties:
>                           input. The default is D0 as input and
>                           D1 as output.
>
> +SPI Controller specific data in SPI slave nodes:
> +
> +- The spi slave nodes can provide the following information which is used
> +  by the spi controller.
> +
> +- ti,spi-cs-per-word: Set chipselect to be toggled on every word send.
> +
> +- ti,spi-turbo-mode: Set turbo mode for this device.
> +
> +
>  Example:
>
> +- SoC Specific Portion:
> +
>  mcspi1: mcspi at 1 {
>      #address-cells = <1>;
>      #size-cells = <0>;
> @@ -20,3 +32,14 @@ mcspi1: mcspi at 1 {
>      ti,spi-num-cs = <4>;
>  };
>
> +- Board Specific Portion:
> +
> +       spi-device at 0 {
> +               #address-cells = <1>;
> +               #size-cells = <1>;
> +
> +               controller-data {
> +                       ti,spi-cs-per-word = <1>;
> +                       ti,spi-turbo-mode = <0>;
> +               };
> +       };
> diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
> index 893c3d7..1ae5009 100644
> --- a/drivers/spi/spi-omap2-mcspi.c
> +++ b/drivers/spi/spi-omap2-mcspi.c
> @@ -731,11 +731,47 @@ static u32 omap2_mcspi_calc_divisor(u32 speed_hz)
>         return 15;
>  }
>
> +static struct omap2_mcspi_device_config *omap2_mcspi_get_slave_ctrldata(
> +                       struct spi_device *spi)
> +{
> +       struct omap2_mcspi_device_config *cd;
> +       struct device_node *slave_np, *data_np = NULL;
> +
> +       slave_np = spi->dev.of_node;
> +       if (!slave_np) {
> +               dev_err(&spi->dev, "device node not found\n");
> +               return ERR_PTR(-EINVAL);
> +       }
> +
> +       data_np = of_get_child_by_name(slave_np, "controller-data");
> +       if (!data_np) {
> +               dev_err(&spi->dev, "child node 'controller-data' not
> found\n");
> +               return ERR_PTR(-EINVAL);
> +       }
> +
> +       cd = kzalloc(sizeof(*cd), GFP_KERNEL);
> +       if (!cd) {
> +               dev_err(&spi->dev, "could not allocate memory for
> controller data\n");
> +               of_node_put(data_np);
> +               return ERR_PTR(-ENOMEM);
> +       }
> +
> +       if (of_get_property(data_np, "ti,spi-cs-per-word", NULL))
> +               cd->cs_per_word = 1;
> +
> +       if (of_get_property(data_np, "ti,spi-turbo-mode", NULL))
> +               cd->turbo_mode = 1;
> +
> +       of_node_put(data_np);
> +       return cd;
> +}
> +
>  /* called only when no transfer is active to this device */
>  static int omap2_mcspi_setup_transfer(struct spi_device *spi,
>                 struct spi_transfer *t)
>  {
>         struct omap2_mcspi_cs *cs = spi->controller_state;
> +       struct omap2_mcspi_device_config *cd = spi->controller_data;
>         struct omap2_mcspi *mcspi;
>         struct spi_master *spi_cntrl;
>         u32 l = 0, div = 0;
> @@ -745,6 +781,11 @@ static int omap2_mcspi_setup_transfer(struct
> spi_device *spi,
>         mcspi = spi_master_get_devdata(spi->master);
>         spi_cntrl = mcspi->master;
>
> +       if (!cd && spi->dev.of_node) {
> +               cd = omap2_mcspi_get_slave_ctrldata(spi);
> +               spi->controller_data = cd;
> +       }
> +
>         if (t != NULL && t->bits_per_word)
>                 word_len = t->bits_per_word;
>
> --
> 1.7.11.7
>
>


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